unless the perp has their name tattooed on their forehead it is impossible for any witness to give a specific identification of them that would eliminate everyone else. that you would make such a request shows how little understanding you have of the basic premises of how the process works.
what the description can do is eliminate 90% of everyone else (non blacks, females, little kids, adults, kids that were at school, midgets, etc)
I'm sure the police have other evidence that we don't know about. Such as the bullet/bullets and probably other things too. Just because they don't tell the news about it doesn't mean they don't have other evidence. I haven't heard the police mention the parents or parent as suspect. I don't think it's right to judge the parents at this time. They are probably still in shock. A lot of you obviously don't understand the physiological effects of shock.
let's try some very simple math based on demographics of the area.
~59 % of the pop is black. ~ 47% is male and ~ 19% is betwqeen the ages of 5-18. some crude extrapolations tell us that only ~ 5% of the population fits this "too general" description.
then take out all the kids who were actually in school that day (typically less than 10% of school kids are absent on any given day) and your "too general" description would only fit about 1/2 of one percent of the population of the area.
IOW..."too general" my ass.